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i2c_eeprom_emul.c 4.09 KiB
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  • /*
     * Simulate an I2C eeprom
     *
     * Copyright (c) 2014 Google, Inc
     *
     * SPDX-License-Identifier:	GPL-2.0+
     */
    
    #include <common.h>
    #include <dm.h>
    
    #include <fdtdec.h>
    #include <i2c.h>
    #include <malloc.h>
    #include <asm/test.h>
    
    #ifdef DEBUG
    #define debug_buffer print_buffer
    #else
    #define debug_buffer(x, ...)
    #endif
    
    DECLARE_GLOBAL_DATA_PTR;
    
    struct sandbox_i2c_flash_plat_data {
    	enum sandbox_i2c_eeprom_test_mode test_mode;
    	const char *filename;
    	int offset_len;		/* Length of an offset in bytes */
    	int size;		/* Size of data buffer */
    };
    
    struct sandbox_i2c_flash {
    	uint8_t *data;
    };
    
    void sandbox_i2c_eeprom_set_test_mode(struct udevice *dev,
    				      enum sandbox_i2c_eeprom_test_mode mode)
    {
    	struct sandbox_i2c_flash_plat_data *plat = dev_get_platdata(dev);
    
    	plat->test_mode = mode;
    }
    
    void sandbox_i2c_eeprom_set_offset_len(struct udevice *dev, int offset_len)
    {
    	struct sandbox_i2c_flash_plat_data *plat = dev_get_platdata(dev);
    
    	plat->offset_len = offset_len;
    }
    
    static int sandbox_i2c_eeprom_xfer(struct udevice *emul, struct i2c_msg *msg,
    				  int nmsgs)
    {
    	struct sandbox_i2c_flash *priv = dev_get_priv(emul);
    	uint offset = 0;
    
    	debug("\n%s\n", __func__);
    	debug_buffer(0, priv->data, 1, 16, 0);
    	for (; nmsgs > 0; nmsgs--, msg++) {
    		struct sandbox_i2c_flash_plat_data *plat =
    				dev_get_platdata(emul);
    		int len;
    		u8 *ptr;
    
    		if (!plat->size)
    			return -ENODEV;
    		if (msg->addr + msg->len > plat->size) {
    			debug("%s: Address %x, len %x is outside range 0..%x\n",
    			      __func__, msg->addr, msg->len, plat->size);
    			return -EINVAL;
    		}
    		len = msg->len;
    		debug("   %s: msg->len=%d",
    		      msg->flags & I2C_M_RD ? "read" : "write",
    		      msg->len);
    		if (msg->flags & I2C_M_RD) {
    			if (plat->test_mode == SIE_TEST_MODE_SINGLE_BYTE)
    				len = 1;
    			debug(", offset %x, len %x: ", offset, len);
    			memcpy(msg->buf, priv->data + offset, len);
    			memset(msg->buf + len, '\xff', msg->len - len);
    			debug_buffer(0, msg->buf, 1, msg->len, 0);
    		} else if (len >= plat->offset_len) {
    			int i;
    
    			ptr = msg->buf;
    			for (i = 0; i < plat->offset_len; i++, len--)
    				offset = (offset << 8) | *ptr++;
    			debug(", set offset %x: ", offset);
    			debug_buffer(0, msg->buf, 1, msg->len, 0);
    			if (plat->test_mode == SIE_TEST_MODE_SINGLE_BYTE)
    				len = min(len, 1);
    
    			/* For testing, map offsets into our limited buffer */
    			for (i = 24; i > 0; i -= 8) {
    				if (offset > (1 << i)) {
    					offset = (offset >> i) |
    						(offset & ((1 << i) - 1));
    					offset += i;
    				}
    			}
    			memcpy(priv->data + offset, ptr, len);
    		}
    	}
    	debug_buffer(0, priv->data, 1, 16, 0);
    
    	return 0;
    }
    
    struct dm_i2c_ops sandbox_i2c_emul_ops = {
    	.xfer = sandbox_i2c_eeprom_xfer,
    };
    
    static int sandbox_i2c_eeprom_ofdata_to_platdata(struct udevice *dev)
    {
    	struct sandbox_i2c_flash_plat_data *plat = dev_get_platdata(dev);
    
    
    	plat->size = fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev),
    
    				    "sandbox,size", 32);
    
    	plat->filename = fdt_getprop(gd->fdt_blob, dev_of_offset(dev),
    
    				     "sandbox,filename", NULL);
    	if (!plat->filename) {
    		debug("%s: No filename for device '%s'\n", __func__,
    		      dev->name);
    		return -EINVAL;
    	}
    	plat->test_mode = SIE_TEST_MODE_NONE;
    	plat->offset_len = 1;
    
    	return 0;
    }
    
    static int sandbox_i2c_eeprom_probe(struct udevice *dev)
    {
    	struct sandbox_i2c_flash_plat_data *plat = dev_get_platdata(dev);
    	struct sandbox_i2c_flash *priv = dev_get_priv(dev);
    
    	priv->data = calloc(1, plat->size);
    	if (!priv->data)
    		return -ENOMEM;
    
    	return 0;
    }
    
    static int sandbox_i2c_eeprom_remove(struct udevice *dev)
    {
    	struct sandbox_i2c_flash *priv = dev_get_priv(dev);
    
    	free(priv->data);
    
    	return 0;
    }
    
    static const struct udevice_id sandbox_i2c_ids[] = {
    	{ .compatible = "sandbox,i2c-eeprom" },
    	{ }
    };
    
    U_BOOT_DRIVER(sandbox_i2c_emul) = {
    	.name		= "sandbox_i2c_eeprom_emul",
    	.id		= UCLASS_I2C_EMUL,
    	.of_match	= sandbox_i2c_ids,
    	.ofdata_to_platdata = sandbox_i2c_eeprom_ofdata_to_platdata,
    	.probe		= sandbox_i2c_eeprom_probe,
    	.remove		= sandbox_i2c_eeprom_remove,
    	.priv_auto_alloc_size = sizeof(struct sandbox_i2c_flash),
    	.platdata_auto_alloc_size = sizeof(struct sandbox_i2c_flash_plat_data),
    	.ops		= &sandbox_i2c_emul_ops,
    };